Recently, for strengthening human's visual sensation, the light sources within electronic devices are used as design fundamentals. For example, a light-transmissible mouse is disclosed in Taiwanese Utility Patent No. M361671. The light-transmissible mouse comprises a transparent upper cover and a light source module. The light source module is disposed within the mouse for emitting light. The light passes through the transparent upper cover to the surroundings. Consequently, the appearance of the mouse is enriched. However, since the light emitted from the light source module has a single light color, the color appearance of the mouse is very monotonous and fails to meet many users' requirements. For solving this drawback, an electronic device capable of producing a light color selected by the user has been developed.
For example, an electronic device capable of producing changeable light colors is disclosed in Taiwanese Utility Patent No. M380500. A light-emitting module is disposed within the electronic device for emitting light with an adjustable light color. Please refer to FIG. 1. FIG. 1 is a schematic circuit block diagram illustrating a conventional light-emitting module, which is disclosed in Taiwanese Utility Patent No. M380500. The light-emitting module 100 comprises a color selection unit 110, a controlling unit 120 and a light-emitting unit 130. The controlling unit 120 comprises a microprocessor 121 and an analog-to-digital converter 122. The color selection unit 110 provides one or more colors to be selected by the user.
As shown in FIG. 1, the color selection unit 110 and the light-emitting unit 130 are electrically connected with the controlling unit 120. After a color is selected by the user through the color selection unit 110, a voltage signal is transmitted from the color selection unit 110 to the controlling unit 120. After the voltage signal is received by the microprocessor 121 of the controlling unit 120, the voltage signal is converted into an analog control signal by the microprocessor 121. By the analog-to-digital converter 122 of the controlling unit 120, the analog control signal is converted into a digital control signal. According to the digital control signal, the light-emitting unit 130 emits light corresponding to the voltage signal. In such way, the appearance of the electronic device exhibits the selected light color.
The conventional technology of changing the light color of the electronic device, however, still has some drawbacks. For example, for controlling the light-emitting unit 130 to produce various light colors, it is necessary to install the controlling unit 120 in the electronic device. Under this circumstance, the power consumption of the electronic device is high and the electronic device is not cost-effective.